A DOUBLE-RECESSED AL0.24GAAS IN0.16 GAAS PSEUDOMORPHIC HEMT FOR KA-BAND AND Q-BAND POWER APPLICATIONS/

A double-recessed 0.2-mum gate-length pseudomorphic HEMT (PHEMT) has b een demonstrated with 500 mW of output power (833 mW/mm of gate periph ery), 6-dB gain, and 35% power-added efficiency (PAE) at 32 GHz. At 44 GHz, the device exhibited 494 mW of output power (823 mW/mm), 4.3-dB gain, and 30% PAE. This level of performance is attributed to excellen t MBE material, optimized epitaxial layer design, and the use of indiv idual source vias and of double recess with tight channel dimensions. Excellent 3-inch wafer uniformity was also observed: dc yield was grea ter than 95% and the interquartile range for all dc parameters was les s than 20% of the median value (most are significantly lower). To the best of our knowledge, the Ka-band result is a new state-of-the-art fo r power transistors.